Children's Vaccines Health Center

Rotavirus Vaccine a Success Story
New Vaccine Dramatically Cuts Severe Cases of Diarrheal Illness in U.S. Children
By Charlene Laino
WebMD Health News
Reviewed by Louise Chang, MD

Oct. 27, 2008 (Washington, D.C.) -- A vaccine against rotavirus, an infectious disease that causes potentially deadly diarrhea in infants, has led to a remarkable drop in hospitalizations and visits to the emergency room, researchers say.

Since it was introduced two years ago, the RotaTeq vaccine has cut the number of new rotavirus cases by 66% to 100%, according to a number of studies.

There's even evidence the vaccine reduced spread of the infectious disease to children who were not immunized, the researchers say.

The findings were presented at a joint meeting of the American Society for Microbiology and the Infectious Diseases Society of America.

"The success of the rotavirus vaccine is a major theme of this meeting," says meeting co-chairman Michael Scheld, MD, of the University of Virginia School of Medicine in Charlottesville.
Rotavirus' Grim Toll

Prior to introduction of the vaccine, rotavirus took a grim toll in both industrialized and developing nations, researchers say. Among some of the statistics cited:

* No. 1 cause of diarrhea-related hospitalizations and deaths in babies and young children
* Responsible for about 400,000 physician visits, more than 200,000 emergency room visits, up to 70,000 hospital admissions, and 60 deaths every year in the U.S. alone
* Causes 2 million hospitalizations worldwide annually
* Blamed for nearly half a million deaths annually in children under 5 years.

Since the vaccine's introduction, though, things have taken a 100% turn for the better, says Christopher Mast, PhD, of Merck Research Laboratories, maker of the vaccine.

A company-funded study of more than 61,000 infants showed that RotaTeq provided complete protection against hospitalizations and emergency room visits because of strains of rotavirus targeted by the vaccine.

"RotaTeq provided 100% protection against hospital and emergency department visits due to rotavirus when administered during routine public health practice," Mast tells WebMD.

The study involved 33,135 infants who were vaccinated and 27,954 who were not.

Costs also fell, he says. Since the vaccine's introduction, expenditures dropped from $12,000 per infant per year in the unvaccinated group to nothing in the vaccinated group.

RotaTeq, which gained FDA approval in February 2006, is an oral vaccine given at 2, 4, and 6 months of age. In June, a second rotavirus vaccine came on the market -- GlaxoSmithKline's Rotarix. It requires only two doses, completed by 4 months of age.

Unlike an earlier rotavirus vaccine that was pulled from the market, the two new vaccines do not appear to raise the risk of intussusception. An emergency condition in which the intestine folds into itself like a telescope, intussusception can cause intestinal blockage from swelling and inflammation.

Other research presented at the meeting confirmed RotaTeq's success story:

* A study by researchers at Quest Diagnostics Inc., of Madison, N.J., showed that 26% of 27,625 rotavirus tests done at company labs around the country were positive for rotavirus in the three years before the vaccine was licensed. In the most recent peak season, which ran from December 2007 to June 2008, only 8% of 21,873 tests were positive.